Īrctodus pristinus inhabited more southerly areas, ranging from northern Texas to New Jersey in the east, Aguascalientes, Mexico to the southwest, and with large concentrations in Florida, the oldest from the Santa Fe River 1 site of Gilchrist County, Florida paleontological sites. The original bones are in the Field Museum of Natural History, Chicago. It has become well known in scientific circles because it was the most nearly complete skeleton of a giant short-faced bear found in America. A giant short-faced bear skeleton has been found in Indiana, unearthed south of Rochester. simus might have been the largest land-dwelling species of Carnivora that ever lived in North America. Remains of the giant short-faced bear, along with Paleo-Indian artifacts and the remains of the flat-headed peccary, stag moose, and the giant beaver were found in the Sheriden Cave in Wyandot County, Ohio. Its fossils were first found in the Potter Creek Cave, Shasta County, California.
Although the early history of Arctodus is poorly known, it evidently became widespread in North America by the Kansan age about 800,000 years ago.Īrctodus simus first appeared during the middle Pleistocene in North America, about 800,000 years ago, ranging from Alaska to Mississippi, and it became extinct about 11,600 years ago. During the Great American Interchange that followed the joining of North and South America, tremarctines invaded South America, leading to the evolution of Arctotherium and the modern spectacled bear ( Tremarctos ornatus). The short-faced bears belong to a group of bears known as the Tremarctinae, which appeared in North America during the earliest parts of the late Miocene epoch in the form of Plionarctos, a genus considered ancestral to Arctodus. The scientific name of the genus, Arctodus, derives from Greek, and means "bear tooth". This characteristic is also shared by the only living tremarctine bear, the spectacled bear. simmus represents a bear in the early stages of cursorial evolution.These species appear to have a disproportionately short snout compared to most modern bears, giving them the name "short-faced." This apparent shortness is an illusion caused by the deep snouts and short nasal bones of tremarctine bears compared with ursine bears Arctodus has a deeper but not a shorter face than most living bears. Forelimb skeletal morphology therefore supports the hypothesis that A. Results herein agree well with previous studies and provide additional evidence for reduced abductor/adductor and supinator/pronator musculature, more restricted parasagittal motion, increased stride length, and lighter and more packed distal elements. simus, extant ursids, and other carnivorans. The study here uses traditional and 3D landmark morphometrics to more completely compare the 3-dimensional shape of the major forelimb elements and their muscle attachment sites between A. While earlier studies have focused on craniodental morphology and simple postcranial indices, it is forelimb morphology that represents a direct compromise between locomotor and foraging behavior. Its more gracile form has led past researchers to myriad intepretations of the locomotion and feeding ecology of this species.
The paleobiology of the Pleistocene North American giant short-faced bear, Arctodus simus, has eluded paleontologists for decades.
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